In the zone
I just did it again today. Used hot RO water.And maybe try to use pure distilled water(from chemist) instead of tap or ro water. It would prevent any minerals from depositing in the mouse buttons also as it is non conductive, any traces left would not do much harm.
Most probably dust is depositing between the surface of switch buttons which causes these issues and gets fixed once removed by water.
EDIT: Worked again!
PS: The G102 feels way natural and better than Corsair Harpoon.